Polar bears are known to consume a wide range of marine mammals, with chicks and bird eggs not featuring prominently in their diet.

So when scientists observed a group of polar bears feeding on a colony of arctic birds in Hudson Bay, they took note. Reporting their findings in the scientific journal, Polar Biology, the researchers speculated that the unusual behavior could be the result of sea ice breaking up earlier in the year, among other factors.

Rising arctic temperatures have caused sea ice, used by polar bears to hunt for seal and other mammals during the winter months, to break apart up to a month earlier than 20 years ago. The early break up happens to coincide with the period when arctic birds, such as snow geese and thick-billed murres, build their nests. Polar bears, finding themselves on shore earlier in the year, have been spotted feeding on chicks and bird eggs on Coats and Southampton Islands. An Environment Canada news story highlights the potential for the bears to increasingly depend on birds as a food source.

Should we be alarmed? Keep in mind that these observations are anecdotal, but they do point to the potential for climate change to impact the delicate balance in the north. As the arctic environment continues to change, complex ecological interactions are being played out with potentially troubling results for birds.